Winning the Buybox as a new Seller

I am having great difficulty winning the Buybox as a new seller and it is causing a lot of problems for my business.

I have followed all the guidance and tips on criteria for winning the Buybox such as price, delivery times, IPI score, account health, feedback score and overall policy adherance etc.

I have a seller rating of 100% but with only 3 reviews (could this be the main factor?). I am trying to build on this but how am I supposed to increase these figures if I cant make any sales in the first place?

It seems to be very difficult for new sellers to prove themselves to Amazon and for their algorithm's to work in the new seller's favour.

Currently my only guaranteed way of winning the buybox is to undercut by about 15-20p which I am reluctant to do out of respect for other sellers and because it will just be a race to the bottom.

Any advice would be greatly appreciated.